GE Industrial Solutions A Series Lighting Control Panelboards nstallation and Wiring - Manual (Page 7)

7
Network Cabling Requirements
Requirements for network cabling are as follows:
Cabling – For BACnet MS/TP and LINKnet networks it is
recommended that network cabling match the following
specifications:
• Balanced 100 to 120 ohm nominal impedance
twisted whielded pair (TSP) cable
• Nominal capacitance of 16 pf/ft or lower
• Nominal velocity of propagation of 66% or higher
Topology. Ensure the MS/TP network cable is installed as
a daisy-chain from one device to the next.
Maximum nodes. The maximum number of devices per
MS/TP network without any repeaters is 50.
Termination boards. A termination board should be
installed at both ends of each MS/TP network segment, or
two per MS/TP or LINKnet network.
Repeater. A repeater is not necessary unless more than 50
nodes will be installed on a network or the MS/TP
network is to be extended beyond 4000 ft (1220 m).
Architecture
The network topology is illustrated in Figure 11. Network
communication setup is covered in the following
subsections.
Figure 11. Network topology.
Ethernet
Connect the Ethernet cable from your network hub to the
Ethernet port on the lighting controller. If there are
multiple controllers (fewer than 100 units), Ethernet
cables can be connected to each, or Ethernet cables can be
connected to some, with the remaining controllers
connected to the Ethernet controllers using NET1-to-
NET1 two-wire RS-485 connections. Remember NET1
connections are daisy-chain only – NO LOOPS. See Figure
11.
RS-232
Connect the cable from the PC or workstation directly to
the individual controller. The remaining controllers are
connected to the RS-232 controller using NET1-to-NET1 2-
wire RS-485 connections. Expect slower updates with lower
baud rates, especially with multiple controllers.
RS-485
Connect the serial cable from the PC or workstation to the
RS-485 adapter, and connect the two-wire output to each
controller’s NET1 connector using the daisy-chaining
method. See Figure 11.
CAUTION: The lighting controller is an
electrostatically sensitive device. Proper ESD
protection (ground strap) should be used when
installing this product to prevent damage.